With the increasing use of integrated circuits in electronic devices that provide different types of information for a variety of different applications, there has been an increasing need to adequately protect sensitive and/or critical information that may be stored within an electronic device to limit access to such information to only other devices that have permission to access the information. A physically unclonable function (PUF) generator is a physical structure generally within an integrated circuit that provides a number of corresponding outputs (e.g., responses) in response to inputs (e.g., challenges) to the PUF generator. There are many different implementation approaches including delay-chain-based PUF generators and memory-based PUF generators. A memory-based PUF generator translates the variations in an array of memory devices, typically either SRAM (static random-access memory) or DRAM (dynamic random-access memory) devices, into a binary sequence. Both methods are based on randomness in physical properties among devices caused by inherent variations in a semiconductor manufacturing process, e.g., geometric dimension and doping concentration.
A leakage-based DRAM PUF generator is reliable and cost effective. However, when a leakage current of such device is dominated by a temperature-dependent sub-threshold current, time required to output a PUF signature as well as its reliability become sensitive to the operational conditions (e.g., temperature). Therefore, it is necessary to develop a leakage-based PUF device which can operate in a wide range of temperatures while providing a fast and reliable response.